/Engine/Plugins/EnhancedInput/Source/EnhancedInput/Public/UserSettings/EnhancedInputUserSettings.h
This does nothing by default.
virtual void OnKeyMappingRegistered ( [FPlayerKeyMapping](API\Plugins\EnhancedInput\UserSettings\FPlayerKeyMapping) & RegisteredMapping, const [FEnhancedActionKeyMapping](API\Plugins\EnhancedInput\FEnhancedActionKeyMapping) & SourceMapping )